Sensors are widely used in electronic devices to measure attributes of the environment and report a measured signal value. For example, U.S. Patent Publication No 20160299200 describes a Hall effect sensor for measuring magnetic fields. However, sensors are typically limited in range and sensitivity over the range, have a limited signal-to-noise level, or can be faulty. For example, current sensors are often optimized either for large-current sensing over a relatively wide signal-value range or for small-current sensing with greater sensitivity over a relatively smaller signal-value range. Some sensors include an analog-to-digital converter that converts a measured, analog value to a digital value having a specific number of bits. The signal value represented by the digital value can have either a large range with smaller specificity (sensitivity) or a small range with greater specificity (sensitivity). Thus, conventional sensor design incorporates a tradeoff between range and sensitivity.
Two solutions presently exist in order to mitigate such tradeoffs. One solution includes an electronic circuit with a dynamic amplification step. Another solution uses two sensors with different sensitivities. For example, WO2012/053296 describes a current sensor with first and second current sensors having different ranges. WO2016/021480 describes a current sensor with first and second magnetic sensors whose output is selected on the basis of a sensor measurement compared to a threshold value. However, the measured value of a sensor is at least partly dependent on the sensor's location in the environment, particularly for environmental attributes such as electrical or magnetic fields, or electromagnetic radiation, leading to confusion as to which sensed value is more representative of the desired environmental attribute. Hence, the first and second magnetic sensors, in this example, might actually measure magnetic fields at different locations.
Sensors also have a signal-to-noise ratio dependent on the sensor and circuitry for processing sensed attribute signal values. It is useful to reduce the signal-to-noise ratio as far as possible.
Sensors can also be defective and provide anomalous signal values or can cease to function entirely. Furthermore, it is helpful, in some applications, to reduce the physical size of the sensor.
There is a need, therefore, for devices, systems and methods for improving sensors that can overcome such deficiencies.